Locking Machine Heads. Made by Grover.The newest addition to the Grover family, these locking machine heads utilize the famous 18:1 Rotomatic design with a "thumb screw" mechanism which locks the string into place. Insert the string through the post hole, wrap around once, then lock by tightening with the thumb screw. 18:1 Gear ratio. Peg Size: 10mm

Perfect replacement for most standard machine heads.Includes all mounting hardware.3 Per Side, Set of 6.